2,369 research outputs found

    Improving Moringa Growth by Using Autochthonous and Allochthonous Arbuscular Mycorrhizal Fungi in Lake Victoria Basin

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    Biological methods such as mycorrhiza biotechnology used for raising and sustaining soil fertility in agricultural ecosystems close to freshwater biomes are gaining attention. However, ubiquitous ecological conditions may subject mycorrhizal management to choices that depend on inoculum sources (autochthonous or cultured). Effects of AMF on growth of M. stenopetala and M. oleifera were evaluated using three native soil types, representative of Lake Victoria basin and a standard substrate. Autochthonous AMF was harnessed from the native soils while allochthonous AMF cocktail was acquired from culture banks of Glomus hoi, G. mosseae and G. intraradices, using Plantago major as plant indicator and trap-culture. The soils were blocked according to tillage intensities. P. major supplied Moringa with AMF inoculum. To facilitate mycorrhization, nitrogen fixing bacteria (NFB) in chickpea rhizobia inoculum was integrated. The hyphopodium assays revealed > 90% arbuscle occupancy in root cortex of plants established in paddy LT soils. AMF inoculation improved growth and biomass of both Moringa species. Autochthonous AMF inoculum had relatively higher biomass turnover compared to cultured AMF. The presence of dark septate endophytes (DSE) in plant biodiversity gave a new insight into target plant performance at plant competition for nutrients. Results reveal that inoculum AMF and NFB are potential candidates in optimizing plant production technology applicable in eco-sensitive-oriented low in-put agriculture

    Hybrid Software Development Approaches in Practice: A European Perspective

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    Agile and traditional development approaches are used in combination in todays software development. To improve the understanding and to provide better guidance for selecting appropriate development approaches, it is important to analyze such combinations in practice. Results obtained from an online survey strongly confirm that hybrid development approaches are widely used in industry. Our results show that hybrid development approaches: (i) have become reality for nearly all companies; (ii) are applied to specific projects even in the presence of company-wide policies for process usage; (iii) are neither planned nor designed but emerge from the evolution of different work practices; and, (iv) are consistently used regardless of company size or industry secto

    Probabilistic Fréchet means for time varying persistence diagrams

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    © 2015, Institute of Mathematical Statistics. All rights reserved.In order to use persistence diagrams as a true statistical tool, it would be very useful to have a good notion of mean and variance for a set of diagrams. In [23], Mileyko and his collaborators made the first study of the properties of the Fréchet mean in (D<inf>p</inf>, W<inf>p</inf>), the space of persistence diagrams equipped with the p-th Wasserstein metric. In particular, they showed that the Fréchet mean of a finite set of diagrams always exists, but is not necessarily unique. The means of a continuously-varying set of diagrams do not themselves (necessarily) vary continuously, which presents obvious problems when trying to extend the Fréchet mean definition to the realm of time-varying persistence diagrams, better known as vineyards. We fix this problem by altering the original definition of Fréchet mean so that it now becomes a probability measure on the set of persistence diagrams; in a nutshell, the mean of a set of diagrams will be a weighted sum of atomic measures, where each atom is itself a persistence diagram determined using a perturbation of the input diagrams. This definition gives for each N a map (D<inf>p</inf>)<sup>N</sup>→ℙ(D<inf>p</inf>). We show that this map is Hölder continuous on finite diagrams and thus can be used to build a useful statistic on vineyards

    WISER Deliverable D3.3-2: The importance of invertebrate spatial and temporal variation for ecological status classification for European lakes

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    European lakes are affected by many human induced disturbances. In principle, ecological theories predict that the structure and functioning of benthic invertebrate assemblage (one of the Biological Quality Elements following the Water Framework Directive, WFD terminology) change in response to the level of disturbances, making this biological element suitable for assessing the status and management of lake ecosystems. In practice, to set up assessment systems based on invertebrates, we need to distiguish community changes that are related to human pressures from those that are inherent natural variability. This task is complicated by the fact that invertebrate communities inhabiting the littoral and the profundal zones of lakes are constrained by different factors and respond unevenly to distinct human disturbances. For example it is not clear yet how the invertebrates assemblages respond to watershed and shoreline alterations, nor the relative importance of spatial and temporal factors on assemblage dynamics and relative bioindicator values of taxa, the habitat constraints on species traits and other taxonomic and methodological limitations. The current lack of knowledge of basic features of invertebrate temporal and spatial variations is limiting the fulfillment of the EU-wide intercalibration of lake ecological quality assessment systems in Europe, and thus compromising the basis for setting the environmental objectives as required by the WFD. The aim of this deliverable is to provide a contribution towards the understanding of basic sources of spatial and temporal variation of lake invertebrate assemblages. The report is structured around selected case studies, manly involving the analysis of existing datasets collated within WISER. The case studies come from different European lake types in the Northern, Central, Alpine and Mediterranean regions. All chapters have an obvious applied objective and our aim is to provide to those dealing with WFD implementation at various levels useful information to consider when designing monitoring programs and / or invertebrate-based classification systems

    A framework for the simulation of structural software evolution

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    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2008 ACM.As functionality is added to an aging piece of software, its original design and structure will tend to erode. This can lead to high coupling, low cohesion and other undesirable effects associated with spaghetti architectures. The underlying forces that cause such degradation have been the subject of much research. However, progress in this field is slow, as its complexity makes it difficult to isolate the causal flows leading to these effects. This is further complicated by the difficulty of generating enough empirical data, in sufficient quantity, and attributing such data to specific points in the causal chain. This article describes a framework for simulating the structural evolution of software. A complete simulation model is built by incrementally adding modules to the framework, each of which contributes an individual evolutionary effect. These effects are then combined to form a multifaceted simulation that evolves a fictitious code base in a manner approximating real-world behavior. We describe the underlying principles and structures of our framework from a theoretical and user perspective; a validation of a simple set of evolutionary parameters is then provided and three empirical software studies generated from open-source software (OSS) are used to support claims and generated results. The research illustrates how simulation can be used to investigate a complex and under-researched area of the development cycle. It also shows the value of incorporating certain human traits into a simulation—factors that, in real-world system development, can significantly influence evolutionary structures

    Physical Conditoins in Orion's Veil II: A Multi-Component Study of the Line of Sight Toward the Trapezium

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    Orion's Veil is an absorbing screen that lies along the line of sight to the Orion H II region. It consists of two or more layers of gas that must lie within a few parsecs of the Trapezium cluster. Our previous work considered the Veil as a whole and found that the magnetic field dominates the energetics of the gas in at least one component. Here we use high-resolution STIS UV spectra that resolve the two velocity components in absorption and determine the conditions in each. We derive a volume hydrogen density, 21 cm spin temperature, turbulent velocity, and kinetic temperature, for each. We combine these estimates with magnetic field measurements to find that magnetic energy significantly dominates turbulent and thermal energies in one component, while the other component is close to equipartition between turbulent and magnetic energies. We observe molecular hydrogen absorption for highly excited v, J levels that are photoexcited by the stellar continuum, and detect blueshifted S III and P III. These ions must arise from ionized gas between the mostly neutral portions of the Veil and the Trapezium and shields the Veil from ionizing radiation. We find that this layer of ionized gas is also responsible for He I absorption in the Veil, which resolves a 40-year-old debate on the origin of He I absorption towards the Trapezium. Finally, we determine that the ionized and mostly atomic layers of the Veil will collide in less than 85,000 years.Comment: 43 pages, 15 figures, to be published in Ap

    Psychosocial work environment and antidepressant medication: a prospective cohort study

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    <p>Abstract</p> <p>Background</p> <p>Adverse psychosocial work environments may lead to impaired mental health, but it is still a matter of conjecture if demonstrated associations are causal or biased. We aimed at verifying whether poor psychosocial working climate is related to increase of redeemed subscription of antidepressant medication.</p> <p>Methods</p> <p>Information on all antidepressant drugs (AD) purchased at pharmacies from 1995 through 2006 was obtained for a cohort of 21,129 Danish public service workers that participated in work climate surveys carried out during the period 2002–2005. Individual self-reports of psychosocial factors at work including satisfaction with the work climate and dimensions of the job strain model were obtained by self-administered questionnaires (response rate 77,2%). Each employee was assigned the average score value for all employees at his/her managerial work unit [1094 units with an average of 18 employees (range 3–120)]. The risk of first-time AD prescription during follow-up was examined according to level of satisfaction and psychosocial strain by Cox regression with adjustment for gender, age, marital status, occupational status and calendar year of the survey.</p> <p>Results</p> <p>The proportion of employees that received at least one prescription of ADs from 1995 through 2006 was 11.9% and prescriptions rose steadily from 1.50% in 1996 to the highest level 6.47% in 2006. ADs were prescribed more frequent among women, middle aged, employees with low occupational status and those living alone. None of the measured psychosocial work environment factors were consistently related to prescription of antidepressant drugs during the follow-up period.</p> <p>Conclusion</p> <p>The study does not indicate that a poor psychosocial work environment among public service employees is related to prescription of antidepressant pharmaceuticals. These findings need cautious interpretation because of lacking individual exposure assessments.</p

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    Compensation of Strong Thermal Lensing in High Optical Power Cavities

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    In an experiment to simulate the conditions in high optical power advanced gravitational wave detectors such as Advanced LIGO, we show that strong thermal lenses form in accordance with predictions and that they can be compensated using an intra-cavity compensation plate heated on its cylindrical surface. We show that high finesse ~1400 can be achieved in cavities with internal compensation plates, and that the cavity mode structure can be maintained by thermal compensation. It is also shown that the measurements allow a direct measurement of substrate optical absorption in the test mass and the compensation plate.Comment: 8 page

    Risk stratification by endocrinologists of patients with type 2 diabetes in a Danish specialised outpatient clinic:a cross-sectional study

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    BACKGROUND: To target optimised medical care the Danish guidelines for diabetes recommend stratification of patients with type 2 diabetes (T2D) into three levels according to risk and complexity of treatment. The aim was to describe the T2D population in an outpatient clinic, measure the compliance of the endocrinologists’ to perform risk stratification, and investigate the level of concordance between stratification performed by the endocrinologists and objective assessments. METHODS: A cross-sectional study with data collected from medical records and laboratory databases. The Danish risk stratification model contained the following criteria: HbA(1c), blood pressure, metabolic complications, microvascular and macrovascular complications. Stratification levels encompassed: level 1 (uncomplicated), level 2 (intermediate risk) and level 3 (high risk). Objective assessments were conducted independently by two health professionals, and compared with the endocrinologists’ assessments. In order to test the degree of concordance, we conducted Cohen's kappa, McNemar’s test for marginal homogeneity, and Bowker’s test for symmetry. RESULTS: Of 245 newly referred patients, 209 (85 %) were stratified by the endocrinologists to level 1 (16 %), level 2 (55 %) and level 3 (29 %). By objective assessments, 4 % were stratified to level 1, 51 % to level 2 and 45 % to level 3. Of 419 long-term follow-up patients, 380 (91 %) were stratified by the endocrinologists to level 1 (5 %), level 2 (57 %), level 3 (38 %). By objective assessments, 3 % were stratified to level 1, 58 % to level 2 and 39 % to level 3. The concordance rate between endocrinologists’ and objective assessments was 63 % among newly referred (kappa 0.39; fair agreement) and 67 % for long-term follow-up (kappa 0.45; moderate agreement). Among newly referred patients, the endocrinologists stratified less patients at level 3 compared to objective assessments (p < 0.0001). There were no significant differences in marginal distribution within long-term follow-up patients. CONCLUSION: Type 2 diabetes patients, newly referred to or allocated for long-term follow-up in the out-patient clinic, were mainly intermediate and high-risk, complicated patients (96 % and 95 %, respectively). Compliance of stratification by endocrinologists was high. The concordance between endocrinologists’ and objective assessments was not strong. Our data suggest that clinician-support for stratification level categorisation might be needed
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